基于形态特征和ITS序列对7个鹅膏菌属菌株的分类鉴定

以采自浙江省丽水地区的7个鹅膏菌属菌株作为研究材料,在基于形态特征进行初步鉴定的基础上,对7种鹅膏菌的rDNAITS区段进行克隆测序和序列特征比较分析。进一步对ITS序列进行核酸序列数据库GenBank同源性检索比对,将从GenBank检索获得的9个最相似物种的ITS序列连同7种鹅膏菌的ITS序列一起作系统发育分析。结果表明:基于ITS序列对f6、f9和f493个菌株的分子鉴定支持了基于形态特征的鉴定结果,对f5的分子鉴定不支持形态鉴定的结果,f8为鹅膏菌属内某种,f66为鹅膏菌属内某种,并与Amanitafulva,A.atrofusca,A.orientifulva3种鹅膏菌的亲缘关系较近,f7与另外6种鹅膏菌的亲缘关系相差甚远。研究结果提示基于分子水平上的ITS序列分析不能单方面作为大型真菌分类鉴定的可靠依据,可以作为基于传统形态学分类鉴定的辅助参考依据。

A Primary Studies on Classification and Identification of Seven Amanita Species Based on Morphological Characteristics and ITS Sequences of rDNA

Seven species of Amanita,collected in Lishui of Zhejiang province,China,were identified primarily based on morphological characteristics.The rDNA ITS regions of these species were cloned and sequenced,and the characteristics of ITS sequences were compared and analyzed.The ITS sequences were BLAST matched with GenBank database on homology and the seven ITS sequences,together with nine reference sequences obtained from the GenBank database,were used to construct a phylogenetic tree.The results demonstrated that the ITS sequence analysis supported the identification based on morphological characteristics for most of the species of Amanita on the species level or on the genus level.But for one species of Amanita,there were significant differences between identification based on morphological characteristics and molecular data.The ITS sequence analysis and phylogenetic tree also indicated genetic relationship among the seven species of Amanita.The present study suggests ITS sequence analysis could not be used as an only proof,but it is a very useful supplementary tool for the classification and identification of macrofungi based on morphological characteristics.